Support context manager protocol for traced iterator APIs

[guming-learning]

Description

OpenAI SDK now returns Stream object for streaming Chat Completion API, which is a ContextManager as well as an Iterator.
When we wrap it for tracing, we need to ensure the wrapped object support both. Otherwise, client code leveraging context manager functionality will fail.

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Testing Guidelines

• Pull request includes test coverage for the included changes.

[github-actions]

promptflow-tracing test result

 12 files   12 suites   7m 40s ⏱️
 20 tests  20 ✅ 0 💤 0 ❌
240 runs  240 ✅ 0 💤 0 ❌

Results for commit c980736.

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[github-actions]

promptflow SDK CLI Azure E2E Test Result migu/context-manager

  4 files    4 suites   4m 8s ⏱️
243 tests 204 ✅  39 💤 0 ❌
972 runs  816 ✅ 156 💤 0 ❌

Results for commit c980736.

♻️ This comment has been updated with latest results.

[github-actions]

SDK CLI Global Config Test Result migu/context-manager

6 tests   6 ✅  1m 19s ⏱️
1 suites  0 💤
1 files    0 ❌

Results for commit c980736.

♻️ This comment has been updated with latest results.

[github-actions]

promptflow-core test result

0 tests   0 ✅  0s ⏱️
0 suites  0 💤
0 files    0 ❌

Results for commit c980736.

♻️ This comment has been updated with latest results.

[github-actions]

Executor Unit Test Result migu/context-manager

796 tests   796 ✅  3m 43s ⏱️
  1 suites    0 💤
  1 files      0 ❌

Results for commit c980736.

♻️ This comment has been updated with latest results.

[github-actions]

Executor E2E Test Result migu/context-manager

246 tests   240 ✅  5m 0s ⏱️
  1 suites    6 💤
  1 files      0 ❌

Results for commit c980736.

♻️ This comment has been updated with latest results.

[github-actions]

SDK CLI Test Result migu/context-manager

    4 files      4 suites   1h 4m 55s ⏱️
  783 tests   740 ✅  43 💤 0 ❌
3 132 runs  2 960 ✅ 172 💤 0 ❌

Results for commit c980736.

♻️ This comment has been updated with latest results.